Device for the automatic control of the articulation of the knee applicable to a prothesis of the thigh



DC. l5, 1942 P.. FILIPPI DEVICE FOR THE AUTOMATIC CONTROL OF THE A OFTHE KNEE APPLICABLE TO A ROTHESIS OF TH Filed June 24, 1937 1 1 9 .t 2,5 h o Q v 3,9m 216e. TIe Hh LTS U CE2 I T R SMM/M5 DEVICE FOR THEAUTOMATIC CONTROL OF THE ARTICULATION OF THE KNEE APPLICABLE TO APROTHESIS OF THE THIGH Filed June 24, 1937 '2 Sheets-Sheet, 2

Patented Dec. 15, 1942 DEVICE FOB THE AUTOMATIC CONTROL 0F THEARTICULATION OF THE KNEE AP- PLICABLE TO A PROTHESIS 0F THE 'mien PietroFilippi, Macerata, Italy; vested in the Alien Property CustodianApplication June 24, 1937, Serial No. 150,176 In Italy April 3, 1937 9Claims.

This invention relates to a device for the automatic control of thearticulation of a joint in an artiilcial limb, and more particularly tosuchdevices as are applicable to a knee `joint in a prothesis of thethigh.

The general object of the invention is to provide a novel and improveddevice of this character which is of simple and compact construction,light in weight, and easily and automatically operative by the naturalmovements and postures of the body.

Another object of the invention is to provide in a device of this type,mechanism which will permit the knee joint full freedom of movement whendesired, but is capable of being blocked either deliberately orautomatically (as when balance of posture has to be regained inwalking)I and then released for permitting ilection of the joint afterthe limb is extended.

Further objects of the invention include the provision of an extensibleand contractible hydraulic system associated with they joint of theprothesis and adapted to be blocked and released by means of a tensionmember attached to the torso of the wearer and responsive to certaindeliberate and involuntary movements of the body. 1

In its preferred form, the invention contemplates theprovision of ahydraulic cylinder having a piston working therein, one of theseelements being connected to the lower leg portion of the prothesis andthe other to the upper leg portion or thigh. .Valves are provided in thepiston member to permit the by-passing of hydraulic uid, and theactuation of certain of these valves is effected by a tension memberwhich operatively connects a movable portion of the piston with a beltforming part of the harness for attaching the limb to the wearer so thatwhen he leans forwardly, either deliberately or instinctively (as inregaining his balance lost by placing his foot on the ground with theknee bent), or when he lifts the thigh upwardly, the

` connecting tension member actuates the valve to block the contractionof the system. On the other hand, further extension of the joint ispermitted by another valve which is of the one-way or check valve type.f

Other and further objects and features of novelty will be apparent fromthe following speciii- I cation when read in connection with theaccompanying drawings in which one embodiment of the invention isillustrated by way of example.

In the drawings: l'

Figure 1 is a vertical cross-sectional view of i the apparatus properwhich is preferably disposed inside ot the lower leg portion of theartiilcial limb; the parts being in the position affording the kneejoint full freedom of movement;

Figure 2 is a fragmentary view similar to Fisure 1 with the parts in4position to prevent the flection of the articulation;

Figure 3 is a similar view showing the parts in position as whenextension of the hydraulicv device begins;

Figure 4 is a view in side elevation of the whole artiileial limb whenraised as high as possible;

Figure 5 is a similar view showing the leg in vertical position; and

Figure 6 is a view also in side elevation showing the limb bent. A

The prothesis or articial limb may be of any suitable form and issomewhat diagrammatically shown in Figures 4, 5 and 6 as comprising theupper leg or thigh portion I4 and the lower leg portion 3 hingedtogether to provide an articulated knee joint indicated at 3'. The limbis attached to the torso of the wearer by a suitable harness whichincludes the belt 23.

The novel means for controlling the articulation of the joint 3'comprises the hydraulic cylinder I which is closed at its lower end bythe plug 2 which is secured as by means of the ring 2 to the lowerportion of the lower leg member 3. The cylinder is provided at its upperend with a bushing 4 provided with a leather packing ring 5 and stufdngbox arrangement 6 through which a piston rod is adapted to pass. thecylinder I there is adapted to reciprocate the piston 1 to which thereis threaded as at 1' the tubular piston rod 8 which extends through thepacked opening at the upper end of the cylinder and is attached to thebifurcated element I2 carried by the pivot pin I3 which is connected tothe base of the thigh portion I4 of the limb. A nut I5 serves to varythe connection between the tubular piston rod Il and the member I2 inorder to adjust the degree oi' opening of a control valve as will belater described. -A leather packing ring I0 and bushing II providealtight fit for the piston 1 in the bore .of the cylinder I.

The hollow tubular pistnnrod 8 encloses a rod or shaft 9 which carriesat its lower end a valve assembly for controlling the by-passing of thehydraulic fluid. At the upper end of this shaft 9 there is secured ablock or bracket 2| to which is attached the cable 22 forming a part ofthe tension member by which the valve is operated. The cable 22 passesaround the pulley I9 carried Within.

by an arm I2' provided on the member I2. The cable 22 forms an inelasticportion oi' the tension member which also comprises the elastic part 22'the upper end of which is adjustably attached to the belt 23 in anysuitable manner as at 2l; the inelastic portion 22 of the tension memberextending along the thigh I4 and the elastic portion passing over therear portion of the hips to its point of attachment to the belt.

At the lower end of the shaft 9 which extends through the tubular pistonrod 8, a conical valve 25 is mounted, the valve being provided with aseries of openings 26. The valve 25 is adapted to seat against theconical surface of the annular base portion 21 of the piston and thuscontrol the passage of fluid through the passageways 21', the interiorchamber 29 and the upper series of passageways 28 all providingcommunication between the upper iluid chamber portion I1 and the lowerportion I9. In Figure 1 the valve 25 is shown in the open position whichit occupies during ection of the knee joint. Beneath the valve 25 thereis provided a flexible valve 30 which is preferably faced with leatherand is supported by the washer 3| carried by the end of the valve stemor shaft 9. This washer 3| is also provided with a series of openings32. A spring 33 which is disposed between the upper portion of thepiston 1 and an abutment 33 carried by the shaft 9, serves tocontinually urge the valve 25 downwardly toward open position. By asuitable adjustment of the nut I5 the lowermost position of the block2|, and thus the lower portion of the rod 9, are determined and thus thewidth of the opening I6 aorded by the valve 25 may be varied.

The operation of the controlling device will now be described inconnection with thel three typical positions illustrated in Figures 1, 2and 3 of the drawings. In the iirst position, shown in Figure l, thevalve 25 is open and the hydraulic iiuid may iiow freely through thevalve opening I9 and the passageways and chambers 21', 2B, and 29 to andfrom the upper and lower iluid chambers l1 and I8; in other words, thepiston 1 is permitted to slide within the pump cylinder and allow thefree articulation of the knee joint in either a iiection or extensiondirection.

In Figure 2, the device vis shown wherein the valves 25 and 30 have beenclosed by the upward movement of the shaft 9 under the iniluence of thetension member 22, 22'. In this position the fluid can no longer owthrough the by-pass pas- 'sageways in the piston 1 and contraction ofthe hydraulic system connecting the portions of the limb is prevented.Consequently ilection of the knee joint is also prevented, as forexample when the limb is bent as shown in Figure 6. The wearer may thusrest his whole weight upon the artificial limb while lifting the otherfoot to take a step.

In' the position illustrated in Figure 3, the valve 25 remains closed,but the ilap valve 30 is opened as the knee is stretched or extended,the piston 1 moving upwardly and the hydraulic iiuid ilowing from theupper chamber I1 to the lower chamber I8 through the openings 26 in themain valve body member 25. Thus, the limb which is still in the blockedposition as respects f lustrated in Figure 2.

Tension in the valve actuating member 22, 22' results when the bodyleans forward or when the thigh is lifted, the elastic portion 22 beingextended and the inelastic part 22 drawn tight. As already mentioned,the body may lean forward voluntarily and deliberately, or involun ltarily as in response to the spontaneous reaction engendered by loss ofbalance through insumcient support upon the foot of the prothesis.

The oil or other hydraulic iluid should not occupy the whole of thespace inside the cylinder I but the level should remain slightly belowthe bushing l in order to leave a layer of air in the upper portion ofthe chamber I1 by means of which lthe displacement of the piston 1 iskept more elastic and the leakage of oil between the rod 8 and thepacking 5, B is rendered more diilicult.

The device may be made of any suitable materials but it is suggestedthat the cylinder and its closures may be made of steel and the piston 1may be constructed o f aluminum.

It is understood that various changes and modifications may be made inthe device as illustrated and described herein without departing fromthe scope of the invention as determined by the subjoined claims.

Having thus described the invention, what is claimed as new and4 desiredto be secured by Letters Patent is:

l. The combination with an artificial limb having at least twoarticulated members and means for attaching the limb to the wearersbody, of a device for the automatic control of the joint between saidarticulated members, said device comprising an extensible andcontractible hydraulic system including a cylinder pivotally connectedto one of said members and a piston working in the hydraulic iluidcontained in the cylinder and connected with another of said members, amultiple by-pass valve assembly disposed in said hydraulic system andcontrolling the iiow o1' iluid from one side of said piston to theother, and valve operating means adapted to be connected to the torso ofthe wearer so as to be automatically and positively actuated by thenatural fiection of the torso to operate said valve assembly to preventflow of iluid from one side of the piston to the other to preventcontraction of the system and consequently prevent flection of thejoint, said multiple valve assembly being automatically operative uponmovement of the piston in a direction to extend said system to permit owin the opposite direction to allow further extension of the joint.

2. The combination with an articial limb having at least two articulatedmembers and means for attaclflng the limb to the wearers body, of adevice for the automatic control oi' the joint between said articulatedmembers, said device comprising an extensible and contractible hydraulicsystem including a cylinder pivotally connected to one of said membersand a piston working in the hydraulic uid contained in the cylinder andconnected with another of said members, and a by-pass valve on saidpiston and controlling the iiow of iluid from one side of the piston tothe other, said attaching means including a portion adapted to beapplied to the torso of the wearer, means associated with said attachingmeans and adapted to be operated by iiection of the torso, said meansalso being connected with said bil-Dass valve to actuate the latter toblock the contraction of the hydraulic system and thus prevent flectionof the joint.

3. A device as set forth in claim 2 in which contraction of the systemis prevented by saidv first named valve.

4. The combination with an artificial limb having at least twoarticulated members and means for attaching the limb to the wearersbody, of

a device for the automatic control of the joint between said articulatedmembers, said device comprising an extensible and contractible hydraulicsystem including a cylinder pivotally connected to one of said membersand a piston working in the hydraulic fluid contained in the cylinderand connected with another of said members` and provided with an openingtherethrough, a main valve member carried by said piston, means adaptedto be connected with the torso of the wearer and responsive to thechanges in posture for causing said valve member to close said openingand prevent contraction of the system, said valve member also beingprovided with an opening controlled by a supplemental flap valve adaptedto permit flow in one direction to allow further extension of the systemeven lwhen the main valve member is closed.

5. The combination with an artificial limb having at least two`articulated members and means including a belt for attaching the limbto the wearers body, of a device for the automatic control of the jointbetween said articulated members, said device comprising an extensibleand contractible hydraulic system including a cylinder pivotallyconnected to one of said members and a piston working in the hydraulicfluid contained in the cylinder and connected with another of saidmembers, and a by-pass valve on said piston and controlling the ilow ofiiuid from one side vof the piston to the other, an elasti'c tensionmember adapted to extend along the thigh and hips and connecting saidby-pass valve with said belt, whereby upon occurrence of certain changesin posture of the wearers body, said system is blockedand collapsingflection of the joint prevented.

6. A device as set forth in claim 2 in which the cylinder of saidhydraulic system is only partially full of the hydraulic fluid, a layerof air remaining above the level of the uid for imparting a certainamount of elasticity to the system.

'7. The combination with an artificiallimb having at least twoarticulated members and means including a belt for attaching the limb tothe wearers body, of a device for the automatic control of the jointbetween said articulated members, said device comprising an extensibleand contractible hydraulic system including a cylinder pivotallyconnected to one of said members and a piston working in the hydraulicfluid contained in the cylinder, a tubular piston rod extending throughpacking at one end of the cylinder and connected with another of saidmembers, a by-pass passageway leading through said piston, a mainby-pass valve controlling the passage of hydraulic fluid through saidpassageway from one side of the piston to the other, a valve stemadapted to support said valve and extending through said tubular pistonrod, a tension member secured to one end of said stem and operativelyconnecting the valve to the belt of the wearer, said main by-pass Valvebeing provided with openings therethrough, a flap main by-pass valvecarried by said main valve and adapted to control the flow of hydraulicfluid through the openings in said main Icy-pass valve in one directiononly.

8. An artificial limb including upper and lower members hingedlyconnected, a plunger mounted for reciprocation in one 'of the members,means carried by the other member for reciprocating the plunger when onemember is swung relativeto the other, an incompressible fluid in thepath of the plunger, a valve, and means cont r olled by the movement ofthe artificial limb relative to the body to which it is attached, foropening and' closing the valve to release or to trap the fluid in thepath of the plunger.

9. In an articial limb the lcombination with hingedly connected members,a plunger mounted to reciprocate in one of the members, and cooperatingmeans on the other member and plunger for reciprocating said plungerwhen the members are swung relative to each other, of a liquid in thepath of the plunger, means for attaching one of the members to the bodyof the user for swinging movement, and means controlled by the swingingmovement of the limb relative to the body of the user for successivelytrapping and releasing the uid to lock and unlock the plungerrespectively.

- PIETRO FILIPPI.

